Resistivity Survey

of the

Nevis Jewish Cemetery

The information on this page is taken from "'What are you doing?': Examining a colonial period Jewish cemetery in the Caribbean", a paper given by Michelle Terrell at the 31st Annual Meetings of the Society for Historical Archaeology held in Atlanta January 6-10, 1998.

If you were to visit the small island of Nevis located in the Eastern Caribbean and if you were to take a tour of the popular historic sites of the island you would most certainly visit the 17th- and 18th-century Jewish cemetery in the center of Charlestown, the capital and main port. Here you would gaze upon carved inscriptions in Hebrew, Ladino, and English that bear testimony to the experiences of an uprooted and persecuted religious group.

Glancing around the cemetery you would likely notice that the remaining nineteen grave markers are unevenly distributed within the lot. One lone stone is located in each corner of the property while the majority of the surviving stones are clustered together (Figure 1). On the surface it appears that the Jewish community of Nevis purchased a much larger plot of land than they needed.

Figure 1. Map of the surviving grave markers and the outer wall of the cemetery.

Considering, though, that the cemetery existed for at least 50 years and that the Jewish population in Charlestown numbered as many as 75 to 100 persons during that period, it seems likely that there were additional burials within the cemetery that are no longer marked.

After the Jewish population left the island during the second half of the eighteenth century, the cemetery fell into disuse. In the Nevis Blue Book of 1863 in a collection of remarks on squatting we find the following excerpt: " the peripheries of Charlestown there is an ancient Jewish Cemetery long since disused by persons of that persuasion on which from time to time for more than thirty years past, a number of houses have been erected by squatters." The cemetery continued in this neglected state into the twentieth century. When Rabbi Malcolm Stern visited the island in 1957 he found the cemetery overgrown and delineated by the remains of a single-strand wire fence. Stern and his wife recorded some of the epitaphs on the stones and through their publication in the journal of the American Jewish Archives brought the state of the cemetery to the attention of several philanthropists who set about refurbishing the burial ground, resulting in its rededication in 1971.

Considering the uneven distribution of burials, in conjunction with the presence of broken stones within the cemetery, the paucity of burials from the first quarter of the 18th century when the community was at its supposed peak, and the history of neglect it seemed highly likely that the 19 surviving markers did not reflect the total number of burials. Additional burials may no longer be marked, perhaps because they have become covered over, their markers were not as substantial, or they were removed. It was therefore the goal of the electrical resistivity survey carried out by archaeologists Michelle Terrell (Ph.D. Candidate, Boston University), Eva Hill (M.A., University of Minnesota) and Lynn Newton (M.A. Student, University of Minnesota) to try to identify additional burials.

Grave Marker

The survey used a non-destructive technique known as electrical resistivity. This procedure employs the knowledge that soils and rocks conduct electrical currents differently based on their moisture content, clay content, and porosity, among other factors. Implementation involves applying a current to the ground via two electrodes, while measuring the potential difference through a second set of electrodes. Disturbed ground, such as ditches, allows for a greater buildup of water molecules thereby lowering electrical resistance whereas stone and rubble foundations have high levels of resistance. For this reason resistivity surveys have proven to be an effective method for locating unknown grave sites and foundations.

After having mapped the existing gravestones, trees, and any additional evident ground disturbances within the cemetery, we laid out a uniform 50 cm grid of north-south transects for the survey. This interval of electrical probe separation has proven effective in other surveys in locating historic-period burial shafts. And as the average width of the surviving grave markers is approximately 80 cm, a larger spacing could potentially miss burials. The grid was oriented to the surviving grave markers in order to facilitate the identification of anomalies as traditional Judaic burials tend to oriented east-west, and as orientation of anomalies is often visible at this scale of investigation. Using the Wenner configuration with the probes spaced evenly 1 meter apart, we took readings every 50 cm. We thereby got a reading of the resistance in ohms 1 meter below the surface every 50 cm. The resulting 3,179 readings were then converted to ohm-meters and displayed as raster images.

We anticipated that burial anomalies would be characterized by their size and east-west orientation. Often burials, due to moisture retention within the grave shaft, are typified by low resistivity values. If a mortuary chapel was present, and if it had stone or rubble foundations, it should also appear as an anomaly in the survey data, though most likely one of high resistivity values. Of course that is not quite how things turned out.

Here are the resistance data for the entire cemetery with an overlay of the existing stones and the outer wall of the cemetery in white. Reds and yellows represent high resistance, blues and purples low resistance, and green mid-range (Please note that black represents areas that were not tested and that north is to the right):

Figure 2. Raster image of the resistivity data projected using a normal curve.

Looking at this raster image (Figure 2) of the survey values projected using a normal curve you can immediately see some rather large and quite apparent anomalies: the right-angled linear anomaly of high resistance in the lower left and the clusters of low resistance to the right.

Figure 3. Image of the resistivity data with high (reds) and low (blues) anomalies outlined.

The rectilinear nature of the lows at the right (Figure 3) are typical of disturbed ground associated with former structures. The size of these anomalies - the largest being approximately 9 x 6 meters and the smaller ones 3 x 4 meters - and their arrangement may indicate that these are evidence for the "number of houses" erected by squatters as indicated in the previously mentioned 1863 document. A scatter of artifacts visible on the surface along the eastern wall of the cemetery just to the left of one of the low anomalies contained samples of pearlware, colonoware, blue and green shell-edge, and sponged whiteware confirming a nineteenth-century presence within the cemetery and the likelihood that at least one of the anomalies was domestic in nature and most likely a former squatter's house.

The right-angled anomaly of high resistance values in the lower left corner of the cemetery (Figure 3) is approximately four meters wide and is oriented at the same angle as the house features. This orientation indicates the possibility that the feature is a compact roadbed associated with the former houses. It's abrupt terminus, along with the incomplete anomaly in the lower right, demonstrate the artificial nature of the eastern boundary of the cemetery hinting at the likelihood that the modern cemetery configuration does not reflect the original layout of the cemetery plot and the possibility of additional burials beyond the cemetery walls built in 1971.

But are there possible grave anomalies? Close examination of the normal projection indicates some grave-sized anomalies of higher resistance with an east-west orientation appearing in the upper right and lower left. These values, though, are muted by the extremely high values of the roadbed feature.

Figure 4. Image of the resistivity data with the high anomaly masked and using an equalized projection in order to emphasize high values (red).

By removing, or masking, the values associated with the roadbed and producing a raster image with an equalized projection, thereby equally emphasizing the higher and lower values as much as the mid-range, we get an image in which the highs (shown in red) are brought to the fore (Figure 4). Several grave-shaped anomalies with an east-west orientation now become visible. It is of interest to note that the grave-sized anomalies present in the cemetery were indicated by high resistance as opposed to the expected low resistance of grave shafts. Examination of the extant gravestones within the cemetery indicates that the bases of the slabs are constructed of local stone or brick and it is possible that these anomalies represent buried footings, gravestones, or fill. In order to clarify this image and highlight the potential graves, an additional raster image (Figure 5) was produced of all values over 29 ohm-meters,

Figure 5. Image of all of the values over 29 ohm-meters.

By taking these last two images, the one with the equally stressed high and low values (Figure 4) and the image with all of the values over 29 ohm-meters (Figure 5), and blending them based on the hue and saturation values of the rasters, an image results (Figure 6) in which the grave-sized anomalies are emphasized. Likely grave anomalies with an east-west orientation and high resistance values are here outlined in black.

Figure 6. Blended image of Figures 4 and 5 with potential graves outlined in black.

The result of this survey was the identification of at least 44 possible burials within the cemetery in addition to the nineteen marked burials. There is also the potential for additional burials within the disturbed areas of the squatter's houses and the road-bed, but resistivity data alone can not identify burials within these areas. The revised picture of the cemetery then is one in which the space within the burial ground was indeed used in its entirety (Figure 7) but post-abandonment disturbances and neglect resulted in the present configuration of markers. The resistivity findings also located probable nineteenth-century features in the form of the squatter's homes and a probable associated roadbed. Often verification of resistivity data would take place through excavation, but as there is no impending threat of disturbance to the cemetery no excavation is planned. The knowledge of additional burials within the cemetery will be incorporated into the demographic and spatial analysis of the community and will thereby contribute to a more complete picture of colonial-period Jewish life on the island of Nevis.

Figure 7. Revised image of the cemetery with high (red) and low (blue) anomalies, potential grave locations (green), and the surviving grave markers (white).

The Jewish Community of Nevis Archaeology Project | The Nevis Synagogue Archaeology Project
Nevis History | The Nevis Jewish Cemetery | The Cemetery Resistivity Survey

Michelle Terrell's Homepage | | Revised November 2001

The views and opinions expressed in this page are strictly those of the page author.
The contents of this page have not been reviewed or approved by the University of Minnesota.